The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 01, 2012
Filed:
Oct. 29, 2008
Kouji Fujita, Yokohama, JP;
Kouji Fujita, Yokohama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In an optical disc drive apparatus, when a start time of a tracking pull-in operation is adjusted according to the eccentricity amount of the optical disc, a suitable starting point of the tracking pull-in operation can be always captured and the pull-in operation of the tracking control can be stably performed, without depending on the eccentricity amount of the optical disc. Further, the eccentricity amount and an eccentricity phase are detected from a track zero crossing signal before the tracking pull-in, and an eccentricity compensation signal of the track is added to the tracking control signal. As a result, also in the optical disc with the large eccentricity amount, the tracking pull-in operation can be stably performed.